There has been known a technology that uses a virtual image superimposed on a foreground of a vehicle to notify a driver about a presence of an obstacle such as a pedestrian. The virtual image is superimposed and displayed by a head-up display (HUD) device as described in Patent Literature 1, for example. According to Patent Literature 1, the visual line of the driver is guided toward the obstacle by visual line guide display that shifts an image toward the position of the obstacle.